Threaded fastener with multi-stage torque limiting applicator
US5681135A · kind A · utility
Inventor
Key dates
| Filing date | Jul 20, 1995 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | Jul 20, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B2033/025
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fastener system includes an applicator for engagement by a tool, and a fastener such as a screw having a first surface with first screw threads in a one hand direction for engaging a workpiece. An attachment mechanism is provided to transfer rotational force from the applicator to the fastener and has second and third screw threads in an opposite hand direction to the first screw threads. The second and third screw threads are interfaced to establish a torque of the predefined magnitude prior to the fastener being attached to the workpiece. When the torque applied by the tool exceeds the predefined magnitude, the attachment mechanism begins to unthread and further application of torque from the tool to the fastener ceases, thereby controlling the applied torque to no greater than the predefined magnitude. The attachment mechanism can be used in a variety of applications including flush mounted heads, shallow aperture installations and multistage torque mountings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.